There are several medication types available to reduce the tendency of blood to form clots or clumps. Anticoagulants are also known as "blood thinners" although this refers to viscosity more than dilution.
Some common types of anticoagulants for heart vessel (coronary vasculature) disease, leaky heart valves (aortic and mitral valve regurgitation), and heart related chest pain
) or heart attack
are in the link provided below.